Electric alarm.



PATENTED DEG. Es, 19o?.

F. I. JCHNSON.

ELECTRIC ALARM.

APPLIGATION FILED sEPT.1.19o5.

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PATENTED DEC. 3, 1907.

F. I. JOHNSON.

ELECTRIC ALARM.

APPLIUATION FILED SEPT.1,1905.

'2 SHEETS-SHEET 2.

AIX M(- Alarms, of which the following, with the ac-l UNITED sTATEs PATENT OFFICE.

ELECTRIC ALARM.

Specification of Letters Patent.

Patented Dec. 3, 1907r Application filed-September l1. 1905. Serial No. 276.766.

To all whom 'it may concern:

Be .it known that I, FREDERICK I. JOHN- soN, a-citizen ofthe United States, residing in the town of Barrington, county of Bristol, and State of Rhode Island, have invented a new i and useful Improvement in ElectricI companying sheets of drawings, is a description.

My invention is intended for use in hotels or .other buildings where a number of lodg'ers may each wish to be called by yan alarm at any hour and consists of a clock located in some central placev connected by electric wires with alarms and `dials in the several a lroomsfin` the manner .hereinafter described so that each lodger-may set his dial at the hour'at which he wishes to be calledI and when that hour arrives the 'central clock will automatically make the proper electrical connections to ring the alarm in his room, without ringing other alarms not set for the same time.

,In the accompanying 'drawings is illu'strated a clock and connections sufficient for use at any quarter hour; but it will be' apparent from the. following description that the same principle can be readily used by a further duplicatlon of wires and batteries at as much moreffrequent intervals as desired. It is thought that quarter hour intervals will ordinarily prove satisfactory in practice.

In the drawings, Figure 1 shows my invention diagrammatically and the system of Wiring between the central clock and each room, including dials, bells, 'electric magnets,`etc..; Fig. 2 represents the face of one of the dials located in one of thel lod in rooms; Fig. 3 is areal' view of the dial wit t e cover or backremoved and showing the electric magnets and` that ortion of the wiring necessary to establish t e connections by means of these magnetsas will be more fully explained hereinafter; Fi one of the dia s showing thewires entering therearof the dial vand their distribution to the various contacts, magnets, and bindi posts; Fig. -5 representsthe rear of the cloc shown in Fig. 1 and shows the wiring to oonnect 'the contacts with the line wires; and Fig. 6 is an enlarged cross section of one of the hands and contact pieces and shows the projection attached to the hand for estabishmg 1the ,electrical connection between the 4 is a side sectional view of .hand and the contact as well as ,the wire attached to the latter.

The clock A. (Fig. 1) ,-vsee also Fig. 5-,is fitted with two sets of metallic contact pieces, one set twelve in number may form an inner circle under 'and in such a position that they `may be successively crossed by a projection t of the hour hand B., (Fig. 1), and will commonly form a complete circle, there bein only suilicient spacesA between them for tlie insertion of proper insulating material. These contacts are lindicated by the letter C. and the insulating material' between them by C (see Fig. 5). The other set of contacts are' arranged in a circle outside the first set where they may be reached,

and traversed by the rojection d of`the minute hand D, (Fig. 1 As shown in the drawings'these latter contacts are four in number, one after each quarter of an hour and are indicated by the letter E. (Figs. 1', 4). vAs shown they are made of such a size that the minute hand will be three minutes in traversing each .and consequently will cause the alarm to continue to ring for three minutes unless sooner shut off, as will be described later. It will 'be evident that these contacts maybe made smaller ,or larger as desired, so as to slierten or lengthen the time of contact, and that they may be du licated to any extent the only limitation eing that each'must ave its own wire tothe several rooms and each such battery.

fThe construction of the projection or attachment of the hands B. and D. as well as the contact piece and the attachment of the wire to the latter is shown in Fig,l 6 where W. may be considered as re resenting a cross section of' one of the han s B. or D., X the rojection or attachment made in the bent orm shown so as to always traverse the contact Y., and Z.'v the wire soldered or otherwise attached to theI back of the contact.

In each room is a dial indicated by H. 'in Fig. land shown by itself in Fig. '2.' It has two hands hand -h similarto those of a clock and which can be readily moved by 'the occupant. Under these hands are small contact points, one set of twelve in a circle to correspond with the hours, indicated by the letter K., (seel particularly Fig. 2), which lare so placed that the dummy hour hand will come 1n contact with each as it is revolved. The

wire its own other seto four, indicated by the letter L.,

are Iplaced to represent the quarter hours and are vreached by the dummy minute ,hand which comes into contact with each as it is revolved. f

A set of twelve wires, numbered from 1 to 12 (both included) shown in Fig. 1, connect" the twelve hour contacts ofthe clock with their respective twelve contact points upon the dials, the wires-being numbered in the drawings to correspond with the hour, and

. four other wires numbered 15, 30, 45 and 6() served that four dials are shown in Fig. 1,l

respectively connect the four quarter hour contacts. of the yclock with their respective' uarter hour contact points'upon thedials.

hese wires, as also the two battery wires here-v inafter described may be carried through. the house and to the dials in the several rooms in cable form as indicated in Fig. 4. Inserted in each of the four wires 15', 30, 45 and 60, is a battery to energize its wire when proper contacts are made, and each of these four wires is connected with the wiring lof one of four electro magnets in each room.

A iifth battery is connected with its battery wire, marked N., and'its return-wire,

marked R., with the alarm bell in each room and with the4 armatures-of all the electrol magnets in such manner, that the circuit of this bell battery will be closed whenever any each of which is supposed to be in a separate 'room' of the `house and they are marked Room 1, Room 2 etc. The hands of these dials have been turned to the positions which 'would represent on a clock,' a uarter past six, (room 1), half past six; room 2), a uarter of six, (room 3), and ,six oclock, room 4), respectively, which are supposed to be the times at which the occupants of the several rooms wish to be called. The central clock (Fig. 1) shows the time to be a quarter before six and therefore the circuits required to ring the alarm in the tlird room should be closed, While all others remain o en. The series of hour contacts C. C. on

t e central clock are preferably so arranged that the insulated s aces will occur where the hour hand will cross it between 30 and 45 minutes after the hour, since whenever itis .65 the contact point for six oclockso as to use desired to indicatea quarter before the hour, asa uarter of six, a`person will commonly turn t e dummy hands of a dial as in room 3 of the drawings by placing the hour hand on wire 6 instead of on that for five oclock. 4In

other 'words he will ordinarily think of a quarter' of six insteadof forty-five minutespast five. Accordingly the series of `hour contacts C. C. of the clock in the drawings are so arranged andl at a quarter of six, wire 6 will be the one used for operating the alarm in room 3. The current ilowing in the clock circuit at -a quarter before SiXyS indicated thus and maybe readily followed on Wires 45 ,and 6 from the battery for wire 45 to' Icontact for this wire onthe central clock- (see Fig. i6) through the hands ofthe clock and through the 'contact on the cloclffor the hour six and thence by wire 'tothe'dial in room' 3. It 'then passes through the dummy hands of the dial to the contactfor 45 minutes and thence to wire 45, passes through and energizes the electro magnet in this wire 45 and thence back to the battery. It will be oblserv-ed that the clock circuit in room?, is the only lone closed, since the hands of this dial are the only ones' so4 set as to usewire 45 which is the wire with which the minute hand of the central clock is making the contact to 'close the circuit. In other words the hands of the clock and the .dummy handsof the dials .must correspond before any clock circuitis closed.

The current flowing in the bell circuit is indicated b and maybe readily followed from the ell battery through the wire N. to room 3 where it is connected, as already described, with-'the bell and with the arma' tures of each one of thefour electro magnets. One of these fourmagnets, that in wire 45 is the only one energized and-the onlyone which has attractedl its armature into contact with its contact point to close the cir cuit. The current of this' bell'circuit there-v fore flows through the bell and this armature back to the battery. In the same way thiscurrent would flow through any one of the armatures in any one of the rooms whenever. its electro magnet 1s energizedsoas to draw 1tinto contact with lts contact oi'nt.

It is evident that the alarm wi l be sounded in all rooms set for the same time 4and in no others at that time. wished, the dummy minute or hour hand of ythe dial in that room is so moved as not to be in contact With any of the contact points. Fig. 2 shows a dial with oints forholding the dummy .minute han from revolving when it is set out of contact with any point to which wires are attached, and the hands vas indicated in this figure aresetnot to ring the alarm.

A consideration of my invention audits method of o eration w1ll. show that it enables me to a d dials in an unlimited number of further rooms without increasing the number of wires because of such addition.

I claim as my invention;`

1. A system of alarms consisting of a cen- Whereverno call is tral clock rovided with contacts traversed by its hands, dials with contacts corresponding to those of the clock and means for connecting the dial contacts, and wires and batteries connecting the contacts-of the clock with those y of the dials; the` clock hands, wires and batteries and connecting means of any dial forming a number of circuits one of which is closed whenever the hands of the clockindicate a time for which the contacts.

of that dial are connected; a oupof relay magnets for each dial, one o dial, and an alarm circuit with its battery connected to the" several rela niagnets and including a bell for each dial whereby the bell will be sounded whenever any one of the clockl circuits forthat dial is closed.

2. In an alarm, a clock having two sets of electrical contacts, one traversed by the hour hand and the other by the minute hand, the hour and minute hands being in electrical contact, a series of dials having two series of responding which is in. serted in each ofthe clock circuits for that' of the contacts traversed bythe hour hand of the clock with the corresponding contact of all the-dials, and the other set of wires connecting each one of the contacts traversed by the minute hand of the clock with the corcontact of all of the dials, an electro magnet for each dial inserted in each of one set'of wires, an alarm and a circuit to operate the alarm connected with the armar ture's'and their contacts in such manner that the alarm circuit will be closed whenever a'ny of the -magnets are energized, and suitable electrical means for energizing the several circuits.

FREDERICK I. JOHNSON.

Witnesses: j

WM. R. TILLINGHAST,V ARTHUR A. THOMAS. 

